Embodiments of the present invention relate generally to the field of ultrasound inspection systems, and specifically, to a method and system for determination of geometric features in objects.
Use of ultrasound beams in the field of non-destructive testing (NDT) for objects is well known and widely used. Objects such as pipes, solid rods, metal sheets, and metal billets are often inspected through the use of ultrasound beams. Ultrasound inspections are used to determine the presence of geometric features such as welds, porosity, corrosion, slag, cracks, and welding defects in the objects.
In ultrasound inspection the object is exposed to ultrasound beams from transducers placed across the length of the object. Responses to the incident ultrasound beams from different parts in the object are collected by the transducers. The amplitudes of the responses are then analyzed to locate geometric features in the object.
In practical applications, an object is passed through an array of transducers arranged in a particular order to transmit ultrasonic beams into the object with various angles of incidence. Every region of interest within the object to be inspected is passed through this configuration of transducers to generate responses to the ultrasound beams transmitted from each transducer. Hence, interrogation of each object yields a large amount of data during testing. The large amount of data thus received is utilized to generate response charts that plot the amplitudes of the responses against positions of the geometric features in the object with respect to a reference point on the object. The reference point is typically fixed by an operator of the inspection system. Thus, to accurately locate a geometric object, the operator has to manually sift through multiple response charts that display output obtained from the geometric features as a result of the ultrasound beams from different transducers in the configuration.
In typical ultrasound inspection systems designed to inspect hollow pipes, for example, 34 ultrasound transducers are arranged to inspect the pipe. Each transducer scans the pipe and generates geometric feature responses at fixed points along the circumference of the pipe. Response data generated for one transducer for one pipe, thus, requires several kilobytes of memory storage space. Response data from the inspection system for the entire pipe, therefore, amounts to requiring megabytes of memory space.
To handle such voluminous data generated for every inspected object by these inspection systems, installation of a data management system is required. Data management systems that handle data loads of a typical inspection setup handling hundreds of test objects everyday tend to be expensive owing to the amount of data being generated and processed. To avoid expenses related to these data management systems, ultrasound inspection systems store only a part of the data obtained from the transducers by selecting specific positions in the object to generate response charts. For example, in certain systems maximum amplitudes observed at locations between fixed distances in the object are used to generate the response chart. These data reduction techniques add errors to localization of geometric features in objects since the location of the geometric feature is now determined as a function of the fixed distance as opposed to an exact location.
Moreover, the operator spends a lot of time analyzing the data obtained from inspection systems to localize the geometric feature in the object. Errors are introduced in the localization of geometric features as a result of manual interpretation of the response charts. Further, operator costs are also multiplied and added to the cost of utilization of the current-day inspection systems.
Hence, there is a need for a method and system to analyze the limited data obtained from inspection systems and presenting the geometric feature output in a form that reduces operator efforts in localization of the geometric features.